2E3, a new marker that selectively identifies porcine CD4+ naive T cells

Abstract

We describe a novel antigen recognized by mAb 2E3 selectively expressed in the periphery by a subset of porcine CD4+ T cells. Both, CD4 +CD8α- and CD4+CD8αlow T cell subpopulations express this antigen. CD4+2E3+ T cells show phenotypical and functional characteristics of naïve cells. The majority of them are CD29low, CD45RAhigh, CD49d low, CD11alow, CD18low, and SLA-II -. After mitogen activation CD4+2E3+ T cells express high levels of IL-2 mRNA, but only traces of IFN-γ or IL-4 mRNA. Indeed a minor percentage of cells stained positive for IFN-γ when assessed by flow cytometry. Moreover, CD4+2E3+ T cells did not proliferate in response to the recall antigen lysozyme, although they did efficiently to the mitogen ConA. By contrast, CD4+2E3 - T cells show phenotypical and functional characteristics of primed cells. They express markers associated to a memory phenotype, respond to the recall antigen lysozyme, and produce high amounts of IFN-γ and IL-4. © 2004 Elsevier Ltd. All rights reserved.